In December, Google announced they will be personalizing all Google results by default. SEOs rightfully were a bit on edge after that announcement, but we did link to an old study on how personalized results impact rankings, overall.

The study has been revised and posted at the Huomah Blog. I won't go through all the points, but the conclusion is that currently, the personalized changes are so minor that it is not worth SEOs freaking out about them. The overall conclusion of this study stated:

We shouldn’t be changing how we approach things ultimately… Above the fold is the real estate that’s prime (what else is new?). It may be the measuring that we will have to adapt. You will need to find ways to check rankings from a few locales and discern a mean average instead of a definitive placement.